I ran into a similar situation with 1993 Upper Deck baseball cards a few years back also. I bought a bunch of 5,000 ct box of sports cards with about 1500 1993 Upper Deck baseball cards in one of them and most of them were stuck together in solid bricks from the humidity where they were stored. None of the other various issues were stuck like the 1993 UD baseball did except for a mid 1990s Playoff football issue. When I tried to separate them.............which was no easy task, I assure you.......they left white specks on the neighboring card. The fronts looked like they were shot during a snow storm. I tried different things including the freezer method and nothing worked for me. Hopefully, you'll have better luck then I did.
I ended up just tossing them as they were unsalvageable. I only paid $3 for each 5,000 ct box so it was not a loss for me as all the other cards were fine. Just the 1993 Upper Deck baseball and the one Playoff football product were ruined.
Please let us know if the freezer method worked for you. I am curious to find out after my experience with the same card issue